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authorriastradh <riastradh@NetBSD.org>2021-06-16 00:21:17 +0000
committerriastradh <riastradh@NetBSD.org>2021-06-16 00:21:17 +0000
commitbbdda93be2f0bfefe91466b398fe42700a6ea284 (patch)
treee75e77046575209dbb21f73d0bc44c61ec0ec6c0 /sys/dev/ic/wi.c
parent5a96957fa793651c8e7093a5a4c2fcae87232af2 (diff)
if_attach and if_initialize cannot fail, don't test return value
These were originally made failable back in 2017 when if_initialize allocated a softint in every interface for link state changes, so that it could fail gracefully instead of panicking: https://mail-index.NetBSD.org/source-changes/2017/10/23/msg089053.html However, this spawned many seldom- or never-tested error branches, which are risky to have around. And that softint in every interface has since been replaced by a single global workqueue, because link state changes require thread context but not low latency or high throughput: https://mail-index.NetBSD.org/source-changes/2020/02/06/msg113759.html So there is no longer any reason for if_initialize to fail. (The subroutine if_stats_init can't fail because percpu_alloc can't fail either.) There is a snag: the softint_establish in if_percpuq_create could fail, potentially leading to bad consequences later on trying to use the softint. This change doesn't introduce any new bugs because of the snag -- if_percpuq_attach was already broken. However, the snag can be better addressed without spawning error branches, either by using a single softint or making softints less scarce. (Separate commit will change the signatures of if_attach and if_initialize to return void, scheduled to ride whatever is the next convenient kernel bump.) Patch and testing on amd64 and evbmips64-eb by maya@; commit message soliloquy, and compile-testing on evbppc/i386/earmv7hf, by me.
Diffstat (limited to 'sys/dev/ic/wi.c')
-rw-r--r--sys/dev/ic/wi.c15
1 files changed, 4 insertions, 11 deletions
diff --git a/sys/dev/ic/wi.c b/sys/dev/ic/wi.c
index 787fcc481a9..602ce27ce55 100644
--- a/sys/dev/ic/wi.c
+++ b/sys/dev/ic/wi.c
@@ -1,4 +1,4 @@
-/* $NetBSD: wi.c,v 1.255 2020/01/30 04:56:11 thorpej Exp $ */
+/* $NetBSD: wi.c,v 1.256 2021/06/16 00:21:18 riastradh Exp $ */
/*-
* Copyright (c) 2004 The NetBSD Foundation, Inc.
@@ -99,7 +99,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: wi.c,v 1.255 2020/01/30 04:56:11 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: wi.c,v 1.256 2021/06/16 00:21:18 riastradh Exp $");
#define WI_HERMES_AUTOINC_WAR /* Work around data write autoinc bug. */
#define WI_HERMES_STATS_WAR /* Work around stats counter bug. */
@@ -370,7 +370,7 @@ wi_attach(struct wi_softc *sc, const uint8_t *macaddr)
static const uint8_t empty_macaddr[IEEE80211_ADDR_LEN] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
- int s, rv;
+ int s;
sc->sc_soft_ih = softint_establish(SOFTINT_NET, wi_softintr, sc);
if (sc->sc_soft_ih == NULL) {
@@ -546,11 +546,7 @@ wi_attach(struct wi_softc *sc, const uint8_t *macaddr)
/*
* Call MI attach routines.
*/
- rv = if_initialize(ifp);
- if (rv != 0) {
- aprint_error_dev(sc->sc_dev, "if_initialize failed(%d)\n", rv);
- goto fail_2;
- }
+ if_initialize(ifp);
ieee80211_ifattach(ic);
/* Use common softint-based if_input */
ifp->if_percpuq = if_percpuq_create(ifp);
@@ -588,9 +584,6 @@ wi_attach(struct wi_softc *sc, const uint8_t *macaddr)
ieee80211_announce(ic);
return 0;
-fail_2:
- callout_destroy(&sc->sc_rssadapt_ch);
-
fail: splx(s);
softint_disestablish(sc->sc_soft_ih);
sc->sc_soft_ih = NULL;